Field of the Embodiments of the Invention
Embodiments of the present invention generally relate to audio signal processing and, more specifically, to an autonomous audio calibration system.
Description of the Related Art
Audio systems, such as systems used in music venues, movie theaters, and sports stadiums, typically include tens or hundreds of speakers, the output of which must be carefully calibrated in order to ensure a pleasant and relatively uniform audio experience across a wide variety of listening positions. Consequently, such audio systems often include advanced digital signal processing platforms that enable a sound engineer to precisely adjust the sound pressure level, frequency characteristics, phase, etc. of each speaker included in the audio system. Accordingly, using a digital signal processing platform, a sound engineer is able to control the sound output of each speaker to compensate for speaker location, frequency response, acoustic characteristics of the venue, and other factors that may affect the audio experience at certain locations within the listening environment.
In order to calibrate an audio system for use in a particular listening environment, an audio engineer must acquire sound measurements at multiple locations within the environment. Specifically, in order to acquire each sound measurement, the audio engineer typically positions a calibration microphone on a microphone stand at the desired location and plays a series of audio samples through the speakers. The sounds recorded by the calibration microphone are then analyzed (e.g., via a comparison to the original audio sample) in order to determine which adjustments (e.g., adjustments to sound pressure level, frequency characteristics, phase, etc.) need to be made to which speakers.
Although the calibration technique described above enables an audio engineer to compensate for complex acoustic environments and varied listening positions, the calibration process is extremely time-consuming. For example, in a large venue, such as a sports stadium or amphitheater, acquiring sound measurements from enough locations within the listening environment to perform an accurate calibration may take several weeks. Furthermore, calibration of an audio system that is performed before a performance—when a venue is relatively unoccupied—may produce unsatisfactory results when the venue is populated with hundreds of listeners, each of which absorbs sound and, thus, affects the acoustic characteristics of the venue. As result, even when a comprehensive calibration of an audio system is performed beforehand for a particular venue, the listening experience produced by the audio system during a live performance may be suboptimal.
As the foregoing illustrates, techniques that enable an audio system to be more effectively calibrated would be useful.